Automatic safety brake



Sept. 8, 1953 A. H. GENTER AUTOMATIC SAFETY BRAKE Filed Jan. 10, 1951 Patented Sept. 8, 1953 UNITED STATES PATENT OFFICE.

I 2,651,387 AUTOMATIC SAFETY BRAKE Albert H. Genter, Mount Lebanon, Pa. Application January 10, 1951, sernmo. 205,410

2 claims. (01.. Isa-481i My invention relates to an automatic safety brake which is to be applied to a car or train of cars which are drawn up or lowered on an inclined track, such, for instance, as the entry slope of a mine or other inclined roofed passageway. Where a car or train of cars is being moved along, either up or down, such an inclined track, in case the draft cable breaks or other traction means fails,-the cars are free todescend the track at great speed, often resulting inthe death or serious injury to persons riding on the cars and the derailment and wreakage of the cars and loss of their contents. Many such serious accidents have occurred, especially in slope tunnel mines.

- My invention comprises a contact shoe mounted in one of the cars, preferably a specially equipped car which may be coupled to a train of cars, and which shoe is arranged to be elevated into frictional contact with the roof of the passageway, in case traction power is accidentally released from the train and a run away occurs. A centrifugal governor controlled by the speed of the latter is mounted in the car which is provided with the shoe, and causes the elevation of the shoe into contact with the roof of the slope and brings the train of cars to a complete stop.

In the preferred embodiment'of my invention the shoe is pivotally mounted on a horizontal axis on the upper end of a lever, the lower end of which lever is pivotally attached to a portion of the car interior, so that when the lever is swung towards its vertical position the shoe will come into and be held in contact with the roof. To elevate the lever towards the vertical and thus bring the shoe intofrictional contact with the. passage roof, I prefer to provide a single acting pressure cylinder and piston device, mounted in the car, andhavin-g its piston rod pivotally connected to the lever intermediate of the length of the latter. A compressed air tank is mounted. in the car and isv connected by a pipe or duct with the rear end of the cylinder and a valve is fitted in the pipe. A centrifugal governor is mounted within the car and is actuated by sprocket and chain connection with anaxle or wheel of the car, and the governor is so adjusted that when the car attains a predetermined run away speed the governor opens the valve, thereby admitting pressure to the rear of the cylinder, thus elevating the shoe into frictional contact with the slope roof and bringing the car to a stop.

Preferably a. hand valve is provided in the pipe connecting the pressure tank to the cylinso that when the pressure in to the rear end of the der, to prevent the release of pressure from the cylinder from accidentally releasing the shoe untilthe traction means are repaired.

In the accompanying drawings, which illustrate a practical embodiment of the principles of my invention, r

Fig. I is a longitudinal vertical section showing a car provided with my automatic safety brake device, showing the brake shoe retracted out of its operative position, and

Fig. 2- is a similar view showing the shoe raised into contact with the slope roof to halt the run awaycar and the train in which it may be coupled, and

Fig. 3 is a detail on enlarged scale showing the means for attaching the end of the connecting rod tothe valve connecting the pressure tank to the single-acting cylinder.

Referring tothe drawings, t inclined track of the tunnel orroefed passage along which the train of cars is being raised or lowered, as in the entry of a slope nine, and 2 indicates the roof ofthe tunnel or slope which is substantially parallel with the track. The reference numeral 3 indicates a car carrying the safety brake mechanism. This is preferably a special car coupled to a burden bearing car or a train of such cars loaded with coal or other substances and to be drawn. up or lowered down the inclined track- I which may be on a twenty percent incline to the horizontal, or it" may be a passenger car loaded with miners. A tank 4 containing compressed air is located within the car 3. This may be a replaceabietank, a tank falls below operate the safety roof indicates the the necessary amount to brake, a fresh tank may be substituted, or, if desired, the tank. may be permanently mounted in the car 3, and means, such as an air compressor, not shown, driven by the movement of the car may be used to maintain the necessary pressure in the tank.

The tank 4 is connected by a pressure pipe 5 cylinder 6 mounted within the car ason the deck or platform 1. The cylinder 6 is provided with a single-acting piston 8. The piston 8 is provided with a piston rod 9 which extends through the front end of the cylinder and is connected to an intermediate portion of a lever Ill. The lower end of said lever is pivotally mounted within the car 3, as for instance on platform 1. A gudgeon I l is mounted on the outer end of the piston rod and engages a longitudinal slot l2 in the lever l 0 to slide along said slot when the lever I0 is being swung,

On the upper end of lever to is the frictional brake shoe l3 pivoted to said lever on a horizontal axis. The brake shoe is provided with a central extended flat surface to increase the contact area engaging the roof 2 when the lever is moved counterclockwise from its position illustrated in Fig. 1 into its position illustrated in Fig. 2 engaging the roof 2 of the slope. At its front and rear, as shown in the drawing the shoe is provided with downwardly curved wings |4-l4 which enable the shoe-to slide into flat contact with the roof rather than to dig into the latter as the shoe moves into contact with the roof, to halt T the car.

A gravity centrifugal governor is shown at 15 connected as by sprockets andchain I61 to the axle or wheel of the car 3. The sliding collar H on the spindle l8 of the governor is connected to stationary members at either side of the track, but this is impractical where the passageway is relatively wide, and at best the upsetting of the cars is the result. Again, it has been proposed to provide a brake arm with a serrated contact surface which, in the case of a runaway, is forced down against the surface of the track, but the effect would be to elevate the car and capsize the car or train of cars. The like result would follow if the car be provided with a trailing drag bar which is intended to dig into the track if the movement of the cars in a runaway is downwardly.

In the present invention the pressure is not I applied merely in a downwardly direction, but

the car is held by pressure applied against the one arm of a bell crank lever l8a pivoted at.

its apex to a portion of the car 3 while the second arm of the lever is operatively connected to the stem of a valve 20, in the pipe 5, by the link 19.

The end portion of the link I!) adjacent the valve 20 is provided with a longitudinal slot I9a which is slidably engaged by a pin 2 la extending laterally from the lever of valve 20. Thus lost motion of the link l9 is provided for preventing the governor from opening the valve 20 to admit pressure into the rear of cylinder 6 and thus force the brake shoe against the mine roof, unless the car attains a predetermined runaway speed. This governor is arranged so that when the speed of travel of the car 3 exceeds the safety maximum, as when the traction cable drawing the train of cars up the slope or loweringthem thereon breaks, the governor will open the valve 20, admitting pressure to the cylinder 6 and causing the lever ID to be swung counterclockwise, bringing the shoe l3 into contact with the roof 2 of the slope and halting the travel of the train of cars. As the movement of the run away car lessens and the collar l1 rises on the spindle l8 of the governor, the link 19 will not close the valve 20 because of the leeway afforded by the slot l9a. After the wheels of the car are blocked to prevent resumption of movement, and the .valve 20 is manually closed, the valve 22 may be opened to permit the escape of pressure from the cylinder so that the shoe 13 may be retracted from contact with the roof 2.

The numeral 23 indicates a pressure gauge on tank 4 to indicate the available pressure in said tank, and whether a fresh tank should be substituted.

In the prior art numerous means and methods to prevent a runaway of a traveling vehicle have been proposed. Thus means for adding to the pressure between the wheels and the track rails have been suggested, but have not gone into use in slope mines because the momentum of a runaway train of cars on a slope of at least twenty degrees would be so great that the cars would promptly jump the track and result in a serious accident to men and equipment. In some cases it has been proposed to provide shoes or contact members which, when a runaway occurs, engage roof and also against the track, and the braking action does not tend to lift the car from the track, but acts by wedging the car against the track and also against the roof of the tunnel.

Therefore a positive braking effect is automatically produced which will safely halt the movement of the car or train or cars, without injury to the men who may be aboard the train, or.to the valuable equipment, thus preventing injury without tearing up the track or spilling the contents of the cars.

I claim:

1. A vehicle roof brake comprising, a mine car, a brake shoe having a top surface to frictionally engage and slide along the roof of a mine, lever means pivoted to the car and the under side of the brake shoe to raise the latter into engagement with the roof of a mine when extended, a fluid actuated servomotor mounted on the car and having piston means connected to said-lever means, and control means actuated by the movement of the car to supply fluid under pressure to said servomotor to actuate said piston means and extend the lever means to force the shoe upwardly into frictional engagement with the roof of a mine to retard the movement of the car, the force applied through the brake shoe on the mine roof reacting through the mine car and its wheels to retard the same.

2. The structure of claim 1 characterized in that said control means includes a governor operated by a wheel of the mine car in accordance with the speed of the mine car. I

ALBERT H. GENTER.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 614,346 Reynolds Nov. 15, 1898 705,623 Stevens July 29, 1902 1,098,014 Carter May 26, 1916 1,254,297 Allott et al Jan. 22, 1918 1,269,983 Verbitsky June 18, 1918 1,549,303 Gurney Aug. 11, 1925 1,923,203 Hirvonen Aug. 22, 1938 2,500,931 Curtis Mar. 21, 1950 FOREIGN PATENTS Number Country Date 708,291 Germany July 17, 1941 

